For horizontal sight offset (HSO), the radius R is measured from which point?

For horizontal sight offset (HSO), the radius R is measured from which point?

• A. Center of the curve
• B. Centerline of inside lane
• C. Outer edge of shoulder
• D. Transition point of vertical curve

Answer: (B)

For horizontal sight offset (HSO), the radius R is measured from the centerline of the inside lane. This measurement is critical in highway design, particularly in assessing visibility and safety on curved sections of roadway. The centerline of the inside lane is chosen because it represents the closest path a vehicle traveling through the curve will take to the edge of the road. Since HSO is concerned with ensuring adequate sight distance for drivers, establishing the radius from this point allows for the evaluation of sightlines in terms of driver perception and safe stopping distances. By taking this reference point, transportation engineers can ensure that there are sufficient sightlines for drivers to see any potential obstacles or changes in the road environment that could affect safety. This concept helps integrate horizontal alignment design with vertical elements to optimize the safety and effectiveness of roadway features, ensuring that the geometry supports adequate visibility for all drivers.

For horizontal sight offset (HSO), the radius R is measured from the centerline of the inside lane. This measurement is critical in highway design, particularly in assessing visibility and safety on curved sections of roadway.

The centerline of the inside lane is chosen because it represents the closest path a vehicle traveling through the curve will take to the edge of the road. Since HSO is concerned with ensuring adequate sight distance for drivers, establishing the radius from this point allows for the evaluation of sightlines in terms of driver perception and safe stopping distances. By taking this reference point, transportation engineers can ensure that there are sufficient sightlines for drivers to see any potential obstacles or changes in the road environment that could affect safety.

This concept helps integrate horizontal alignment design with vertical elements to optimize the safety and effectiveness of roadway features, ensuring that the geometry supports adequate visibility for all drivers.